Scientific understanding about climate change continues to advance, from the complex interactions that affect the planet’s weather to the effects we are feeling now and may experience in the future. Our knowledge is enhanced both by new published research and the release of new comprehensive assessments by the U.S. National Climate Assessment and the U.N. Intergovernmental Panel on Climate Change.

We must continue to build on this information, as the effects of climate change are not trivial. The Department of Commerce’s Bureau of Economic Analysis estimates at least one third of the U.S. Gross Domestic Product is weather and climate sensitive, a potential impact of $4 trillion a year (in 2005 dollars). Moreover, with climate change, extreme events such as heat waves, severe storms, and droughts are on the rise, leading to more severe wildfires, billions of dollars in lost productivity for agriculture, flooding on the coasts and near rivers, and lost lives.